SHRINK FILM STAGING SYSTEM AND METHOD

Abstract

A method of delivering film to a tubular shrink film applying machine involves the use of one or more containers that may include wheels enabling film transport, where film is unwound from rolls into the containers. A machine for dispensing tubular shrink film from rolls into containers in a controlled manner is also provided.

Description

TECHNICAL FIELD

This application relates generally to tubular shrink film application machines and, more specifically, to a staging system and method for tubular shrink film used in such machines.

BACKGROUND

A typical tubular shrink sleeve applying apparatus includes a roll of tubular shrink film that is delivered by film drivers over a mandrel assembly. Sleeve drivers interact with rollers in sleeve drive slots of the mandrel to move the tubular film downward along the mandrel assembly. The film is cut to length by a cutter then ejected downward off the mandrel assembly onto a container passing by on a container conveyance mechanism. A downstream application of heat can then be used to shrink the film onto the container.

The films used come on a large roll. To feed the material into the machine the needed amount of film must be unrolled and pulled into the machine. This is problematic due to starting and stopping a large roll and keeping minimum web tension as not to snap the film. Also problematic is the need to splice in a new supply roll once all the film on the current roll has been used. It is common practice to run the film through a large festoon roller system to allow for some film accumulation. This film accumulation is what the machine runs off of while the operator makes a splice. However, the festoon roller system is quite large, and takes up a significant amount of floor space on the factory floor, where space is limited and use of all space comes at a cost. Moreover, the festoon roller systems only provide a limited amount of time within which an operator must make a splice (e.g., typically only thirty seconds or less after the film roll in use is fully unwound). If the operator is unable to make the splice in the allotted time for whatever reason, such as encountering splicing problems or dealing with another issue on the factory floor, then the sleeving machine must be stopped. Because sleeving machines must operate at very high speeds (e.g., typically feeding films at a rate of at least 400 feet per minute) in order to be cost-effective in terms of productivity, any cessation of machine operation potentially adversely impacts the bottom line for production efforts.

It would be desirable to provide a tubular shrink film staging system and method that makes splicing operations simpler and/or reduces or eliminates the need for large festoon roller systems.

SUMMARY

In one aspect, a method of delivering film to a tubular shrink film applying machine involves: (i) unwinding a first roll of tubular shrink film having an external leading end and an internal trailing end into a first bin including wheels to permit the first bin to be rolled by an operator from one position to another (e.g., on a factory floor), wherein the leading end of the first roll of tubular shrink film is held proximate to or externally of an upper opening of the first bin as remaining tubular shrink film of the first roll is unwound into the first bin to produce a first loaded bin in which both the leading end and the trailing end are accessible after the unwinding procedure is completed; (ii) moving the first loaded bin into position at a film feed station of a tubular shrink film applying machine; and (iii) connecting the trailing end of the tubular shrink film to feed into the tubular shrink film applying machine.

In another aspect, a method of preparing tubular shrink film for use in a tubular shrink film applying machine involves: unwinding a roll of tubular shrink film having an external first end and an internal second end into a container, wherein the first end of the tubular shrink film is held proximate to or externally of an upper opening of the container as remaining tubular shrink film of the roll is unwound into the container to produce a loaded container in which both the first end and the second end of the tubular shrink film are accessible via the upper opening after the unwinding procedure is completed.

In a further aspect, a machine for unwinding tubular shrink film from a roll includes a film roll support having a roll of shrink film thereon. A film receiving volume has an upper opening through which shrink film can be delivered into the volume. A film guide arm is mounted above the film receiving volume and movable back and forth through a path to deliver shrink film into the volume in a layered manner as the shrink film is drawn off of the film roll.

In yet another aspect, a film feed system associated with a tubular shrink film applying machine includes first and second containers. The first container includes a first supply of tubular film therein. A first end of the first supply of tubular film protrudes from an upper end of the first container, a first vertical film extent leads downward within the first container toward a bottom of the first container, a first stacked film extent leads upward within the first container toward a second end of the first supply of tubular film that also protrudes from the upper end of the first container. The second container includes a second supply of tubular film therein. A first end of the second supply of tubular film protrudes from an upper end of the second container, a second vertical film extent leads downward within the second container toward a bottom of the second container, a second stacked film extent leads upward within the second container toward a second end of the second supply of tubular film that also protrudes from the upper end of the second container. The second end of the first supply of tubular film is fed into the tubular shrink film supplying machine, the second container is positioned near the first container, and the first end of the first supply of tubular film is spliced to the second end of the second supply of tubular film such that when the first supply of tubular film is completely drawn into the tubular shrink film applying machine the second supply of tubular shrink film will immediately follow.

In another aspect, a tubular shrink film supply package includes a box defining a film holding volume, a closed lower end and an upper end. A length of tubular film is contained within the box. The length of tubular film includes a first film end located adjacent to or protruding from the upper end of the box, a vertical film extent leading downward within the box toward a bottom of the box, a stacked film extent leading upward within the box toward a second film end located adjacent to or protruding from the upper end of the box.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a schematic depiction of film delivery from a roll into a container;

FIG. 2 is a schematic depiction of an embodiment in which the container is a movable bin;

FIG. 3 is a schematic depiction of the use of such movable bins in a factory including a shrink film applying machine;

FIG. 4 is a schematic depiction of one embodiment in which the container is a box;

FIG. 5 is a schematic depiction of another embodiment in which the container is a box;

FIG. 6 shows a crease feature of a film return loop;

FIG. 7 is a partial schematic view of one embodiment of a tubular shrink film roll unwind machine;

FIG. 8 is a side elevation of the machine of FIG. 7;

FIGS. 9 and 10 show the machine of FIG. 7 with film guide arm at opposite ends of the arcuate path; and

FIG. 11 is a schematic partial depiction of another machine embodiment in which the film guide arm reciprocates linearly.

DETAILED DESCRIPTION

Referring to the schematic view of FIG. 1, a roll of tubular shrink film 10 is shown being unwound into a container 12. The roll has a tubular core 14, an internal film end 16 (adjacent the core 14) and an external film end 18 that can be used to draw film 20 off of the roll. This operation depicts a method of preparing tubular shrink film 20 for use in a tubular shrink film applying machine by unwinding the roll 10 of tubular shrink film 20 into the container 12 while the end 18 of the tubular shrink film is held proximate to or externally of an upper opening 22 of the container 12. In the illustrated embodiment, the film end 18 extends over an edge of the container as the remaining tubular shrink film 20 of the roll is unwound into the container 12 to produce a loaded container in which both the film end 18 and the film end 16 are accessible via the upper opening 22 after the unwinding procedure is completed. In an alternative embodiment, a film grip or capture mechanism could also be located internally of the container, proximate the upper opening 22, such as at location 24. Thus, a key feature is that the film is loaded into the container to achieve a first in, last out arrangement that also facilitates splicing operations. Thus, the external (normally leading) end of film on a film roll and the internal (normally trailing) end of film on the film roll see role reversals after loading into the container in that, for purposes of subsequent use, what was the internal end on the film roll becomes the leading end of the tubular film for purpose of feeding into a sleeve applying machine. The configuration and type of container used could vary widely.

Referring to FIG. 2, in one embodiment, the container may be formed by a portable bin 12′ having a set of wheels 30 that enable the bin 12′ to be readily moved across a factory floor 32 from one location in the factory (e.g., a film roll unwind location) to another location in the factory (e.g., a film infeed station of a tubular shrink film applying machine). In this embodiment, the manner in which the film is fed into the container is not overly important, provided both ends 16 and 18 of the film remain freely accessible, and therefore the film may be permitted to fall down into the bin 12′ in a free fall manner. As shown, film end 18 extends from the upper opening 22′ of the bin and leads (via vertical film portion 34) down to a bottom 36 of collected film in the bin, and the film end 16 extends from the upper opening 22′ of the bin and leads to a top 38 of collected film in the bin. Using these types of movable bins provides an ability to perform the film roll unwind operation at the factory where the tubular shrink film application machine is located, as suggested in the schematic layout shown in FIG. 3.

In particular, a roll 10-1 of tubular shrink film (having an external leading end and an internal trailing end) is unwound (e.g., either manually by automated machine) into a bin 12′-1 (of the type including wheels), wherein the leading end of the roll 10-1 is held proximate to or externally of an upper opening of the bin 12′-1 as remaining tubular shrink film of the roll 10-1 is unwound into the bin 12′-1 to produce a loaded bin 40-1 in which both the leading end and the trailing end of the film are accessible. The loaded bin 40-1 is then moved (per arrow 42-1) into position at a film feed station 44 of a tubular shrink film applying machine 46. The trailing end of the tubular shrink film 20 is then connected to feed into the tubular shrink film applying machine. This connection is typically made by splicing the end with another film end that is already feeding into the machine, but in some cases may involve actually snaking the film end through the machine as part of an initial film input operation to the machine 46. As suggested, this operation can be repeated multiple times for multiple film rolls (e.g., rolls 10-1, 10-2 and 10-3) to produce multiple loaded bins (e.g., 40-1, 40-2, 40-3) that are moved (e.g., per arrows 42-1, 42-2, 42-3) from a roll unwind station 48 of the factory to the film feed station 44. It is contemplated that the roll unwind station 48 may typically include just one roll unwind machine that is operated to sequentially load film into the multiple bins 12′-1, 12′2 and 12-3, but more than one roll unwind machine could be used.

As shown, the multiple loaded bins may be positioned successively at the feed station 44, with splices 50 made between the film lengths of each loaded bin. Thus, numerous splices can be made in advance (i.e., without having to wait for one source of film to be nearly depleted at the film infeed station 44 of the machine 46. When any bin becomes depleted of film, it can be moved back to the unwind station 48 to receive film from another film roll.

As suggested in FIG. 3, a typical tubular shrink film applying machine will include a label cut and apply station 52 that is positioned over a conveyor mechanism 54 that carries sleeveless containers 56 past the station where sleeves are applied, and then carries the sleeved containers 56′ on to a shrink station 58 (e.g., a shrink tunnel) where heat is applied (e.g., using hot air or other heat applying systems) to cause the sleeves to shrink tightly onto the containers.

Referring to the schematic of FIG. 4, in another embodiment the container may be a box 12″ (e.g., a box suitable for holding the film for the purposes of shipment from a film supplier to a film consumer (e.g., the factory where the film is used)). In this embodiment, it is desired to make effective use of the volume within the box, so the film is unwound and fed into the box 12″ in a layered manner as shown. As shown, film end 18 extends from the upper opening 22″ of the box and leads (via vertical film portion 60) down to a bottom 62 of collected film in the box, and the film end 16 extends from the upper opening 22″ of the box and leads to a top 64 of collected film in the box, with the film 20 being nicely layered within the box 12″.

As shown, an interior bottom of the box may include an upwardly extending curved base 70 for receiving the film. The purpose of the curved base is to account for the return loops 72 of film at the end of each layer. In particular, the return loops (i.e., the film portions where the film transitions from one layer to another by looping back on top of itself) tend to have a greater thickness because the return loops tend not to flatten completely. When the return loops build up on each other, they tend to cause a depression in the center of the layered film stack, which in turn causes the film to undesirably fall inward upon itself The curved base 70 raises the central portion of the initial layers relative to the return loops 72, and can be sized such that the final layers at the top portion of the box 12″ run generally horizontal, thus avoiding the creation of a layer configuration that will tend to fall inward. In one implementation, the upwardly extending curved base is formed by an insert having an upwardly facing convex surface. In another implementation, the upwardly extending curved base may be formed by a bottom panel of the box, where the bottom panel is curved upward to have an upwardly facing convex surface.

Referring to the schematic of FIG. 5, in another embodiment where the container is a box 12″, the film may be unwound into the box so as to vary lengths of the layers such that at least some return loops 72 are offset from other return loops, thereby aiding in keeping a generally planar stacking of the layers as shown. In the particular illustrated embodiment, a pyramidal (e.g., in two dimensions only) stacking of layers is achieved in the box by using a progressively decreasing layer length. In order to most effectively use this type of layering, a series of pyramidal stacked layer stages 74 may be achieved in the box by using a progressively decreasing layer length for a first series of layers, and then transitioning back to full layer length before again progressively decreasing the layer length. As suggested by the dashed line, the offset layering may also be combined with a curved base feature 70′ if desired.

As shown in FIG. 6, in some cases the return loops of the film may also be formed with a crease feature 76. The crease feature provides an advantage by causing the return loop to lay much more flat. The crease feature may reduce or in some cases eliminate the need for offset layering, though use of the crease feature in combination with the offset is expected.

Referring now to FIGS. 7 and 8, as well as FIGS. 9 and 10, an exemplary machine 80 for unwinding rolls of film into containers is shown. The machine includes a film roll support arm 82 (e.g., which may have a spool form with a removable outer spool plate 83 to enable loading and unloading) having a roll 84 of tubular shrink film thereon. The arm 82 may be motor driven to fee film. A series of film guide rollers 86 are provided to form a dancer arrangement for a film path to a film guide arm 88. The film path extends upward from the dancer arrangement, through a creasing mechanism 87 (which may be optional) over to the guide arm 88 and then downward along the arm. The creasing mechanism may, for example, include one or more clamping devices that operate to temporarily fold portions of the film for creasing, or a rotating mechanism (e.g., rotating member that selectively pushes portions of the film into a creasing die). However, other creasing mechanism arrangements are possible.

A film receiving volume 90 is provided with an upper opening 92 through which shrink film can be delivered into the volume. The film guide arm 88 is pivotably mounted above the film receiving volume 90 and is movable back and forth through an arcuate path to deliver tubular shrink film into the volume in a layered manner as the shrink film is drawn off of the film roll. A drive 94 (e.g., motor and associate linkage to the arm) may be provided for moving of the film guide arm back and forth along the arcuate path under control of a controller 100. A pair of rollers 110 (at least one of which is driven) at the lower end of the guide arm between side plates 112 of the arm create a nip through with the tubular shrink film passes for controlling the feed into the volume 90.

Consistent with FIG. 5 above, the controller may be configured (e.g., programmed) to effect operation of the drive 94 to vary a length of arcuate movement of the film guide arm 88 as film is delivered into the film receiving volume 90 such that at least some return loops of the shrink film are offset from other return loops, thereby aiding in keeping a generally planar stacking of layers. Moreover, the pyramidal layering may be achieved by such controlled arc length variation. The operation of the guide arm and creasing mechanism is coordinated so that creases placed in the tubular film by the creasing mechanism end up properly located in the volume at the end of the arcuate stroke of the guide arm.

The film receiving volume 90 may be defined by frame structure of the machine, into which a removable box of any type may be placed. In the illustrated embodiment, the box is an adjustable box including spaced apart side plates 102 that have upper edges that are arcuate in shape. The spacing between the side plates may be adjusted to accommodate different widths of tubular shrink film. In addition, the floor or bottom of the adjustable box may be vertically movable (e.g., under the control of a motor, linear actuator or other driver of the machine) during film infeed so that the floor starts out vertically near the guide arm 88 and moves downward as the film is layered into the box. The box may be removed when loaded, and replaced with another box to receive a next roll of film. By way of example, the box may be formed of metal components, plastic components or combinations of the two. However, more traditional boxes of cardboard or paperboard (e.g., with flaps that can be closed for sealing the box for shipment) could also be positioned in the machine for loading.

In another embodiment, the plate structures 102 may form part of the machine and a box 104 may be positioned within the volume between the plate structures for loading the film therein. The box be removed via a pivoting or sliding door 106 once the box is loaded with film.

In another embodiment, the film may be loaded into the volume without any box therein, and then dropped into a box below the volume.

It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible. For example, while the exemplary roll unwind machine 80 contemplates a film guide arm that moves pivotably during film loading, it is recognized that per FIG. 11 an alternative would be the use of a film guide arm 200 that does not pivot, but is instead reciprocated back and forth linearly along a path 202 for film loading into a box 204. The arm could be mounted on a track 206 for such purpose and/or could be mounted to a linear actuator for such purpose, but other configurations are also possible.

Claims

1. A method of delivering film to a tubular shrink film applying machine, the method comprising: unwinding a first roll of tubular shrink film having an external leading end and an internal trailing end into a first bin including wheels to permit the first bin to be rolled by an operator from one position to another, wherein the leading end of the first roll of tubular shrink film is held proximate to or externally of an upper opening of the first bin as remaining tubular shrink film of the first roll is unwound into the first bin to produce a first loaded bin in which both the leading end and the trailing end are accessible after the unwinding procedure is completed;moving the first loaded bin into position at a film feed station of a tubular shrink film applying machine; andconnecting the trailing end of the tubular shrink film to feed into the tubular shrink film applying machine.

2. The method of claim 1, further comprising: unwinding a second roll of tubular shrink film having an external leading end and an internal trailing end into a second bin including wheels to permit the second bin to be rolled by an operator from one position to another, wherein the leading end of the second roll is held proximate to or externally of an upper opening of the second bin as remaining tubular shrink film of the second roll is unwound into the second bin to produce a second loaded bin in which both the leading end and the trailing end are accessible after the unwinding procedure is completed;moving the second loaded bin into position near the first loaded bin; andconnecting the trailing end of the second roll of tubular shrink film to the leading end of the first roll of tubular shrink film.

3. The method of claim 2, further comprising: repeating unwinding, moving and connecting operations for one or more additional rolls of tubular shrink film.

4. A method of preparing tubular shrink film for use in a tubular shrink film applying machine, the method comprising: unwinding a roll of tubular shrink film having an external first end and an internal second end into a container, wherein the first end of the tubular shrink film is held proximate to or externally of an upper opening of the container as remaining tubular shrink film of the roll is unwound into the container to produce a loaded container in which both the first end and the second end of the tubular shrink film are accessible via the upper opening after the unwinding procedure is completed.

5. The method of claim 4 wherein the first end of the tubular shrink film extends from the upper opening of the container and leads down to a bottom of collected film in the container, and the second end of the tubular shrink film extends from the upper opening of the container and leads to a top of collected film in the container.

6. The method of claim 5 wherein the container is a bin including wheels that permit the bin to be moved via rolling over a surface, and the film is unwound into the bin in a free fall manner.

7. The method of claim 5 wherein the container is a box, and the film is unwound into the box in a layered manner.

8. The method of claim 7 wherein the film is unwound into the box to vary lengths of layers such that at least some return loops are offset from other return loops, thereby aiding in keeping a generally planar stacking of the layers.

9. The method of claim 8 wherein a pyramidical stacking of layers is achieved in the box.

10. The method of claim 9 wherein a series of pyramidical stacked layer stages is achieved in the box.

11. The method of claim 7 wherein multiple return loops of the layered film are formed with a crease feature.

12. The method of claim 7 wherein an interior bottom of the box includes an upwardly extending curved base for receiving the film.

13. The method of claim 12 wherein the upwardly extending curved base is formed by an insert having upwardly facing convex surface.

14. The method of claim 12 wherein the upwardly extending curved base is formed by a bottom panel of the box.

15. The method of claim 7 wherein the box is adjustable.

16. The method of claim 7 wherein the box comprises metal, plastic, cardboard, paperboard or a combinations of one or more of the same.

17. The method of claim 5 wherein the container is a box and the film is unwound into the box in a layered manner by moving a film guide arm back and forth along a path above the box.

18. A machine for unwinding tubular shrink film from a roll, comprising: a film roll support having a roll of shrink film thereon;a film receiving volume with an upper opening through which shrink film can be delivered into the volume;a film guide arm mounted above the film receiving volume and movable back and forth along a path to deliver shrink film into the volume in a layered manner as the shrink film is drawn off of the film roll.

19. The machine of claim 18 wherein the film guide arm is pivotably mounted and is moved back and forth along an arcuate path.

20. The machine of claim 19, further comprising: a drive for moving of the film guide arm back and forth along the arcuate path;a controller associated with the drive and configured to effect operation of the drive to vary a length of arcuate movement of the film guide arm as film is delivered into the film receiving volume such that at least some return loops of the shrink film are offset from other return loops, thereby aiding in keeping a generally planar stacking of layers.

21. The machine of claim 20 wherein the controller is configured to effect operation of the drive to vary the length of arcuate movement so as to achieve a pyramidical stacking of layers.

22. The machine of claim 21 wherein the controller is configured to effect operation of the drive to vary the length of arcuate movement so as to achieve a series of pyramidical stacked layer stages.

23. The machine of claim 19 wherein the film receiving volume is defined in part by a pair of space apart side walls having upper edges of arcuate shape.

24. The machine of claim 18 wherein the machine includes a film end capture for holding a leading edge of the shrink film external of the film receiving volume as the shrink film is delivered into the film receiving volume.

25. The machine of claim 18 wherein the film guide arm is mounted for movement back and forth along linear path.

26. The machine of claim 18 wherein a film creasing mechanism is located along a film travel path of the machine for selectively placing creases in the film to facilitate layering of the film.

27-35. (canceled)